Hyporeninemia, aldosteronism and hypertension characterize primary aldosteronism due to an aldosterone-producing adrenal adenoma. Patients with this disorder may have an overproduction of prostaglandin E2 by the kidneys that is probably the result of potassium depletion. Inhibition of prostaglandin synthesis did not affect production of aldosterone by the adenoma or production of 17-hydroxycorticosteroids by the adrenal glands. Also, prostaglandin synthetase inhibition did not decrease creatinine clearance or sodium and potassium excretion as it has in other disorders with increased renal synthesis of prostaglandin E2. The results suggest that prostaglandins are not necessary for hypertension or primary aldosteronism.